Product pipe, such as conduit, is often installed underground for accommodating underground utilities, such as fiber-optic cables. To install underground pipe (e.g., water, sewer, gas, etc.), a variety of different methods can be used. One example is Horizontal Directional Drilling (“HDD”), in which a pilot hole is drilled in the ground on a general horizontal path by an HDD machine. Once the pilot hole is complete, the product pipe is connected to the drill pipes and pulled back through the pilot hole.
Another technique called pipe bursting is also utilized for installing underground product pipe. In pipe bursting, an expander head is pulled through a preexisting underground pipe so as to expand and burst the preexisting pipe as it is pulled underground by way of a pulling machine (such as a winch). As the expander head bursts the preexisting pipe, the expander head pulls a new product pipe, which is attached at the rear of the expander head, into the previous location of the preexisting pipe.
Often, in order to attach the product pipe to the drill string in an HDD operation or to the expander head in a pipe burst operation, a pullhead adapter is fused to the product pipe (e.g., welded, adhered, or placed within), attached to the drill string or expander head, and pulled into place underground. Once in place, the portion of pipe that includes the pullhead adapter is cut from the product pipe and a pipe adapter must then be fused on the product pipe so that the product pipe can connect to other piping. The pipe adapter is often configured to join dissimilar pipe materials together such as iron and high density polyethylene (“HDPE”) in a mechanical joint (“MJ”). Such an adapter is often referred to as an MJ adapter. This removal of a portion of the product pipe and pullhead adapter and installation of the MJ adapter is often done in a drilling pit and can be both cumbersome and time consuming.
Therefore, improvements in pullhead adapters are desired.